Jeffrey Sachs's new book (The End of Poverty: Economic Possibilities for Our Time, Penguin Press: New York, 2005) advocates a "Big Push" featuring large increases in aid to finance a package of complementary investments in order to end world poverty. These recommendations are remarkably similar to those first made in the 1950s and 1960s in development economics. Today, as then, the Big Push recommendation overlooks the unsolvable information and incentive problems facing any large-scale planning exercise. A more promising approach would be to design incentives for aid agents to implement interventions piecemeal whenever they deliver large benefits for the poor relative to costs.